What is a common sign of low water supply during firefighting operations?

Answer: B — Decrease in water flow

A common sign of low water supply during firefighting operations is a decrease in water flow. When there is insufficient water supply, the flow rate from the fire apparatus decreases, indicating that the available water is inadequate to meet the demands of the firefighting effort. Firefighters rely on a consistent and adequate flow of water to effectively combat fires, so any noticeable reduction in flow can signal problems such as a failing water source, a blockage in the supply line, or an obstruction in the hydrant. Understanding this relationship helps ensure that firefighters can quickly identify potential issues with water availability, allowing them to take appropriate actions to secure additional water sources or adjust their firefighting strategy accordingly. The other options do not accurately indicate a low water supply. An increase in pump pressure typically suggests that water is available and can be manipulated to optimize flow. Increased hose diameter would not be a sign of low water supply; rather, it could be a tactic used to improve flow rates if water supply allows it. Higher engine RPMs can indicate that the pump is working harder, but this is more related to the operational capacity rather than a direct indicator of low water supply.